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TY - CONF AU - Hofmann, T. AU - Boorman, G.E. AU - Bosco, A. AU - Gibson, S.M. AU - Roncarolo, F. ED - Koscielniak, Shane ED - Satogata, Todd ED - Schaa, Volker RW ED - Thomson, Jana TI - Commissioning of the Operational Laser Emittance Monitors for LINAC4 at CERN J2 - Proc. of IPAC2018, Vancouver, BC, Canada, April 29-May 4, 2018 C1 - Vancouver, BC, Canada T2 - International Particle Accelerator Conference T3 - 9 LA - english AB - A laser-based emittance monitor has been developed to non-invasively measure the transverse emittance of the LINAC4 H⁻ beam at its top energy of 160MeV. After testing several sub-systems of the instrument during linac commissioning at intermediate energies, two instruments are now permanently installed. These instruments use a pulsed laser beam delivered to the accelerator tunnel by optical fibres before final focusing onto the H⁻ beam. The photons in the laser pulse detach electrons from the H⁻ ions, which can then be deflected into an electron multiplier. In addition, the resulting neutral H⁰ atoms can be separated from the main beam by a dipole magnet before being recorded by downstream diamond strip-detectors. By scanning the laser in the horizontal and vertical plane the beam profiles are obtained from the electron signals and the emittance can be reconstructed by the H⁰ profiles at the diamond detectors. This paper describes the final system layout that consists of two independent instruments, each measuring profile and emittance of the H⁻ beam in the horizontal and vertical plane and discusses the preliminary commissioning results. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2357 EP - 2360 KW - laser KW - electron KW - detector KW - emittance KW - linac DA - 2018/06 PY - 2018 SN - 978-3-95450-184-7 DO - 10.18429/JACoW-IPAC2018-WEPAL074 UR - http://jacow.org/ipac2018/papers/wepal074.pdf ER -